Process data preselection (predefined PDOs)

An EtherCAT device usually offers several different process data objects (PDO) for input and output data, which can be configured in the System Manager, i.e. they can be enabled or disabled for cyclic transmission.

From TwinCAT 2.11, for suitable EtherCAT devices (as per ESI/XML description) the process data for input and output can be activated simultaneously through suitable predefined sets via "Predefined PDO assignment".

The EL33xx devices have the following "Predefined PDO" sets in the "Process data" tab (EL3318 shown in the example):

Process data preselection (predefined PDOs) 1: — TwinCAT System Manager with predefined PDO option "Standard"

When selecting "Standard" [A] (or "inputs only", EL3311, EL3312, EL3314)

the input PDOs 0x1A0n are enabled for the corresponding input channels,
the output PDOs 0x160n of Sync Manager 2 [B] are disabled.

Process data preselection (predefined PDOs) 2: — TwinCAT System Manager with the predefined PDO option "External Compensation"

In the "External Compensation" option [A] (or "with ColdJunction Compensation", EL3311, EL3312, EL3314), the input and output PDOs 0x1A0n or 0x160n of the respective channels are enabled.